VANCOUVER - Advocates gathered at a national roundtable on medical marijuana say persistent stigma surrounding the drug has created a significant barrier to scientific research in Canada.

More than 25 organizations representing patients, government and industry are meeting to identify research priorities at the conference hosted by the Arthritis Society in Vancouver.

Jonathan Zaid of Canadians for Fair Access to Medical Marijuana says negative connotations associated with cannabis are a big part of why there's a lack of clinical studies examining its potential as a treatment therapy.

Zaid was diagnosed at 14 with a pain syndrome that causes constant headaches, and he tried dozens of medications before his mom bought him a marijuana joint on his 18th birthday.

He's now 22 and says cannabis isn't a miracle drug but it helps ease his pain and has allowed him to lead a full life, including attending the University of Waterloo and becoming a patient advocate.

Arthritis Society chief mission officer Joanne Simons says the negative sterotype around cannabis must be eliminated because it's a medication that could help people who are living with chronic pain.